A liquid crystal display device usually comprises a liquid crystal cell and a pair of polarizing plates (a light incident side polarizing plate and a light emitting side polarizing plate) which are disposed in a manner of sandwiching the liquid crystal cell. In the case of usual liquid crystal display device modes such as a VA mode and an IPS mode, a pair of polarizing plates are usually disposed in a cross-Nicol arrangement, i.e., disposed so that the absorption axes of the polarizing plates are approximately orthogonal to each other, and designed to give a black imaging (to block transmission of light) in the absence of an electric field.
However, when such a liquid crystal display device is observed from an oblique direction, the absorption axes of the pair of polarizing plates apparently intersect each other at an larger angle (obtuse angle) than a right angle. As a result, light leakage occurs. That is, when the liquid crystal display device is observed from the oblique direction, the black image is more imperfect than the black image when viewed from the front direction. Accordingly, when the liquid crystal display device is observed from the oblique direction, there has been a problem of lower contrast than when the liquid crystal display device is observed from the front direction.
Thus, in order to reduce such light leakage, a liquid crystal display device usually comprises, between a pair of polarizers, a phase difference plate for compensating for light leakage caused by these polarizing plates (appropriately referred to hereinbelow as polarizing plate compensation). As a means of realizing the polarizing plate compensation function, it has been proposed in prior art to interpose a phase difference plate between the pair of polarizer, wherein the phase difference plate has a refractive index Nx in the in-plane slow axis direction, a refractive index Ny in an in-plane direction orthogonal thereto, and a refractive index Nz in the thickness direction which satisfy the relationship of Nx>Nz>Ny. For example, Patent Literature 1 describes stretching of a resin film wherein a shrink film is adhered to one side or both sides of the resin film to form a layered body, and the layered body is then stretched under heating to impart shrinking force in the direction orthogonal to the stretching direction of the resin film. In Patent Literature 1, such a method provides a phase difference plate which satisfies the relationship of 0<(Nx−Nz)/(Nx−Ny)<1.